package main

import (
	"fmt"
	"time"
)

func main() {
	demo := make(map[int]int)

	go func() {
		for j := 0; j < 1000; j++ {
			demo[j] = j
		}
	}()

	go func() {
		for j := 0; j < 1000; j++ {
			fmt.Println(demo[j])
		}
	}()
	time.Sleep(time.Second * 1)
}
